Tooling for a Five-Head Moulder

Advice on spiral cutterheads for quick, clean production of S4S stock. August 31, 2009

We will be installing a 5-head moulder soon to be used primarily for S4S of door parts, including panel staves. Because we widebelt every face that gets finish, we will probably go with spiral insert heads for the top and bottom. The side heads need to give a good finish, so we are thinking straight knives.

Here are my questions. Is aluminum instead of steel a major drawback (or advantage)? Would you specify 2" high side heads, or 4"? This moulder has about 1" axial travel on the side heads, so I guess that you could use most of a 4" cutting edge by swapping heads between right and left.

Also, would it be an advantage to go with matching full-width top and bottom heads to be able to rotate them top to bottom and use the entire head? Any preferences for fast change straight knive heads - like Tersa, Terminus, Lietz, Weinig, etc? We need to run carbide for the type of material we run. Can you recommend a vendor for these heads?

Forum Responses
(Solid Wood Machining Forum)
From contributor R:
First, congrat's on your new moulder purchase, best of luck to you in your new machine. Aluminum advantage on the horizontal spindles carry a lot less weight, putting less of a load on the bearings, resulting in longer bearing life as long as everything is balanced. Yes I would max out the machine's width on these just in case you need the full width of the machine. I would put a 240 mm on the first bottom and 230 mm on the other tops and bottoms. I would prefer 60mm side heads over the 100mm. Reason being that you can use half of it then flip right for left and use the other half without moving the axial adjustment. They also carry less weight. As far as where to get the cutter heads, look around there are a lot of great products to choose from. I think you will find some good deals in this economy.

From Dave Rankin, forum technical advisor:
I use the aluminum spiral heads and they work great. For the side heads, I would consider a shear head with a coated tool steel. This will give you a better finish and longer tool life than a regular corrugated head.

If you use shear they are direction specific. The shear is in the direction to help hold the wood to the table. In this case, I would use 60mm width heads. If you use a regular corrugated head then the 4"(100mm) head would allow you to flip-flop the heads. I would strongly suggest the use of a carbide insert head here. Once again, I would consider a shear action head using either 80 or 100mm inserts. If you go with shear, this would be a custom head. The price would not be out of sight.

If you use a standard straight insert head, the brands you mention all have good histories. I have more often used Terminus and Weinig than the others. There are several other good quality heads that will work that were not mentioned. What make of moulder are you getting? What type of material will you be running? These questions will help in getting other suggestions.

From the original questioner:
Thanks. It is a six year old SCMI Compact 23 out of a cabinet shop. We run cabinet door parts in all common hardwoods, including maple. We also run jatoba commonly for stair parts, etc. - enough that I prefer to go carbide to avoid lots of changeovers. For the shear on the side heads - one dealer that I spoke with offered a dual shear head with 50 mm inserts. Is this worth considering?

From contributor F:
The dual shear, or alternating shear as some people call them, is what I would recommend for the side heads. The cut quality is far superior to straight knife heads and the alternating shear allows the heads to be switched from side to side as others have recommended. As far as the width of the side heads go, I would recommend that you buy heads only as wide as the largest product you plan to run. I only say this because the inserts wider than 60mm, like 80mm and 100mm, take a very large jump in price in comparison to their smaller counterparts. You could buy almost four 50mm inserts for the cost of one 100mm insert.

For the top and bottom heads I would recommend the Terminus or Tersa style heads in full width like Russ said. The advantage to the Terminus or Tersa heads is that you would not have to swap the heads, only the knives to use up the whole cutting length. The tool change time is a great deal shorter with Terminus and Tersa over spiral planing heads as well.

From contributor E:
First of all, congratulations on finding the right machine. The best deal out there right now is from Kanefusa. That is 24 knives per head as they are 4 knife heads. I run their 130 mm heads on my side spindles because I can just swap them out to the other side when they get dull and keep running. I do run a fair amount of 8/4 stock, so the 130 mm works best for me. The Enshin knives that Kanefusa makes have a proprietary coating that greatly extends the edge life compared to regular HSS. Just recently they introduced the Eco Enshin knife that is a carbide version the fits in their head. They sent me a set to evaluate for them and give them some feedback from an end user, and so far they are exceeding my expectations. I also like my Weinig spirals for certain applications and have found them to be far superior to anything else out there.

From contributor C:
I'd like to second contributor F's comment about blade cost. I have a couple of 50mm insert heads and one 60mm. The 50mm knives are $2-3, while the 60mm are around $8 I think.

Your original post said you would be running door parts, including panel staves. I think as nice as the shearing heads would be, you don't warrant the additional cost. The staves, I assume, are getting edge sanded before glue, and wide-belted after glue, so finish isn't as critical. If you are doing cab doors, I would think you will be running a tongue on one side and perhaps an edge detail on the other, rather than just S4S. If you are running passage door stock, again I suspect there will be glue involved down the line, and thus sanding, so finish isn't critical.

Are you pre-planing your stock? If not, steel heads are nice because they have more mass, which helps the head act like a flywheel under a heavy load, which you might get from a hump or heavy board in undressed stock. I really only think this is relevant in profiling; I have some 15/16" cuts that I don't think an aluminum head would enjoy for very long. Those factors and the additional cost would steer me towards a more traditional option.

From contributor F:
Based on what contributor C said I would have to agree that alternating shear tooling may be over-kill. Non-sheared insert heads leave a very nice cut and use less expensive inserts. The alternating shear insert heads require a more expensive insert to get them to cut a true flat surface. This is because a straight knife set on a shear in the head does not cut a straight surface, but a large curve. So the inserts for alternating shear heads have to have a "profile" ground in them to compensate for the shear angle. Alternating shear tooling leaves a surface finish that is almost finish sanded in appearance. So if the material is going to receive either additional cutting operations or sanding operations, then alternating shear tooling is not necessary.

From the original questioner:
Our process calls for S4S, because we run so many different cope, stick, and edge profiles that it is simpler to cope first. Without going too far into the nuts and bolts of the process, we rip first then crosscut panel staves. There is almost always enough tension over a ten foot board to cause some bowing of the cut line. My thought was to change the rip schedule to hit several standard widths, in addition to the rail and stile widths. Then process the staves through the moulder to get them straight and flat. We get the best glue joints by running staves through a power fed edge jointer. Maybe I should be asking what the best side head configuration would be to get edges that can be glued. We use an RF panel clamp for these. Should I stick with steel knives and go to a quick-change head, realizing that I will use up knife edge quickly on the tougher woods?

From contributor O:
To contributor E: have you tried of have any feedback on the Kanefusa Tersa clone? Garniga has a new thick knife insert head that looks interesting. I donít know anything about it other than looking at a show. They use a standard 3mm knife that can be re sharpened many times.

From contributor E:
The Autoplanus head looks interesting. It offers a different solution to the never ending problem of keeping sharp knives in your cutterheads. The drawback is that you have to buy their heads plus a number of spare sets of knives to swap out while the others are being re-sharpened.

Kanefusa will give you a set of heads with a minimum purchase of their knives. Their proprietary coating really extends the life of the knife. I'm getting at least three times the run time out of their knives compared to Tersa knives. As for Kanefusa's Tersa clones with their coating on them, I'm getting much better results with these knives also. I used to run Tersa carbide knives in my jointer but now just use the coated Kanefusa steel knives

Kanefusa was looking for an end user to start using their knives so they could get direct feedback on edge life and give them real world numbers of how many feet of material is run before swapping out knives and they set me up as one of the shops they use. In exchange I get to buy directly at pretty good discounts. So when youíre ready let me know and I'll get you hooked up.

I learned the hard way to not try to save money on cutterheads. I tried two different well known names for some heads. One set I was able to return because they were clearly defective, the other set I had to eat because I never knew how bad they were until I bought Weing spirals to replace them. The only heads that now slip on my machine are either Weinig or Kanefusa.

From the original questioner:
To contributor E: have you tried the Eco-Enshin carbide tipped knives yet? The Enshin does look like a nice head for my sides. Does anyone have experience with Global Tooling's spiral insert heads?

From contributor E:
I'm running the Eco-Enshin right now and am very pleased with the results.

From contributor O:
My take on the Autoplanus is that it might be better for the high volume type millwork operation. Looking at their cost comparison sheet I use nowhere near the quantities they compare. I think someone processing thousands of feet per day might benefit from this system because the cost of knives is less and the 3mm thickness will go more distance. The changeover is not nearly as quick as a Tersa head. As a small company I like the versatility of the Tersa type head. I can switch to carbide in minutes if needed or swap out a slightly worn set for fresh knives for picky work. I am getting closer to needing new knives for the moulder. I have been using the Tegra clones in the jointer and planer. Iím happy with them but still want to try the coated Kanefusa.

From contributor S:
On the shear heads that everyone has mentioned, how do they work on common woods such as red oak, soft and hard maple, poplar, birch, knotty alder, and cherry? These are what I run mostly. Would they work also for the side heads when running casing and base? I use straight knives now but I would like something that would hold up better on the alder wood and ones that have knots. I also see a lot of scrapping action on alder and would this type of knife do a better job? Iím just looking for a way to make my product look better beside going back and hand sanding when I get knicks or see something not perfect.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor M:
A spiral cutter head with carbide inserts with shear cut action is the better solution, either for the side or the top or bottom heads.